
\begin{tikzpicture}[>=latex,line join=bevel,]
  \pgfsetlinewidth{1bp}
%%
\pgfsetcolor{black}
  % Edge: x_6 -> x_7
  \draw [] (82bp,60bp) .. controls (89bp,60bp) and (97bp,60bp)  .. (104bp,60bp);
  % Edge: x_10 -> x_11
  \draw [dashed] (82bp,14bp) .. controls (89bp,14bp) and (97bp,14bp)  .. (104bp,14bp);
  % Edge: x_6 -> x_10
  \draw [] (68bp,46bp) .. controls (68bp,40bp) and (68bp,34bp)  .. (68bp,28bp);
  % Edge: x_9 -> x_10
  \draw [dashed] (32bp,14bp) .. controls (39bp,14bp) and (47bp,14bp)  .. (54bp,14bp);
  % Edge: x_7 -> x_11
  \draw [dashed] (118bp,46bp) .. controls (118bp,40bp) and (118bp,34bp)  .. (118bp,28bp);
  % Edge: x_1 -> x_5
  \draw [dashed] (18bp,92bp) .. controls (18bp,86bp) and (18bp,80bp)  .. (18bp,74bp);
  % Edge: x_2 -> x_3
  \draw [] (82bp,110bp) .. controls (88bp,110bp) and (94bp,110bp)  .. (100bp,110bp);
  % Edge: x_11 -> x_12
  \draw [] (132bp,14bp) .. controls (139bp,14bp) and (147bp,14bp)  .. (154bp,14bp);
  % Edge: x_7 -> x_8
  \draw [] (132bp,60bp) .. controls (139bp,60bp) and (147bp,60bp)  .. (154bp,60bp);
  % Edge: x_1 -> x_2
  \draw [] (36bp,110bp) .. controls (42bp,110bp) and (48bp,110bp)  .. (54bp,110bp);
  % Edge: x_5 -> x_6
  \draw [] (32bp,60bp) .. controls (39bp,60bp) and (47bp,60bp)  .. (54bp,60bp);
  % Edge: x_8 -> x_12
  \draw [] (168bp,46bp) .. controls (168bp,40bp) and (168bp,34bp)  .. (168bp,28bp);
  % Edge: x_5 -> x_9
  \draw [dashed] (18bp,46bp) .. controls (18bp,40bp) and (18bp,34bp)  .. (18bp,28bp);
  % Edge: x_3 -> x_7
  \draw [dashed] (118bp,92bp) .. controls (118bp,86bp) and (118bp,80bp)  .. (118bp,74bp);
  % Edge: x_4 -> x_8
  \draw [] (168bp,96bp) .. controls (168bp,89bp) and (168bp,81bp)  .. (168bp,74bp);
  % Edge: x_3 -> x_4
  \draw [] (136bp,110bp) .. controls (142bp,110bp) and (148bp,110bp)  .. (154bp,110bp);
  % Edge: x_2 -> x_6
  \draw [] (68bp,96bp) .. controls (68bp,89bp) and (68bp,81bp)  .. (68bp,74bp);
  % Node: x_10
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (68bp,14bp) ellipse (14bp and 14bp);
  \draw (68bp,14bp) node {$x_{10}$};
\end{scope}
  % Node: x_11
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (118bp,14bp) ellipse (14bp and 14bp);
  \draw (118bp,14bp) node {$x_{11}$};
\end{scope}
  % Node: x_12
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (168bp,14bp) ellipse (14bp and 14bp);
  \draw (168bp,14bp) node {$x_{12}$};
\end{scope}
  % Node: x_6
\begin{scope}
  \pgfsetstrokecolor{black}
  \pgfsetfillcolor{lightgray}
  \filldraw (68bp,60bp) ellipse (14bp and 14bp);
  \draw (68bp,60bp) node {$x_6$};
\end{scope}
  % Node: x_7
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (118bp,60bp) ellipse (14bp and 14bp);
  \draw (118bp,60bp) node {$x_7$};
\end{scope}
  % Node: x_4
\begin{scope}
  \pgfsetstrokecolor{black}
  \pgfsetfillcolor{lightgray}
  \filldraw (168bp,110bp) ellipse (14bp and 14bp);
  \draw (168bp,110bp) node {$x_4$};
\end{scope}
  % Node: x_5
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (18bp,60bp) ellipse (14bp and 14bp);
  \draw (18bp,60bp) node {$x_5$};
\end{scope}
  % Node: x_2
\begin{scope}
  \pgfsetstrokecolor{black}
  \pgfsetfillcolor{lightgray}
  \filldraw (68bp,110bp) ellipse (14bp and 14bp);
  \draw (68bp,110bp) node {$x_2$};
\end{scope}
  % Node: x_3
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (118bp,110bp) ellipse (14bp and 14bp);
  \draw (118bp,110bp) ellipse (18bp and 18bp);
  \draw (118bp,110bp) node {$x_3$};
\end{scope}
  % Node: x_1
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (18bp,110bp) ellipse (14bp and 14bp);
  \draw (18bp,110bp) ellipse (18bp and 18bp);
  \draw (18bp,110bp) node {$x_1$};
\end{scope}
  % Node: x_8
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (168bp,60bp) ellipse (14bp and 14bp);
  \draw (168bp,60bp) node {$x_8$};
\end{scope}
  % Node: x_9
\begin{scope}
  \pgfsetstrokecolor{black}
  \draw (18bp,14bp) ellipse (14bp and 14bp);
  \draw (18bp,14bp) node {$x_9$};
\end{scope}
%
\end{tikzpicture}
