\begin{tikzpicture} \begin{pgfonlayer}{nodelayer} \node [style=none] (0) at (-3, 3.25) {}; \node [style=none] (1) at (2.5, 0) {}; \node [style=none] (2) at (-5.5, -2.5) {}; \node [style=none] (3) at (1.25, 5.5) {}; \node [style=none] (4) at (0, -4.75) {}; \node [style=none] (5) at (5.75, 2.75) {}; \node [style=none] (6) at (7.75, -4.25) {}; \node [style=none] (7) at (1.25, 0) {}; \node [style=none] (8) at (3.25, 0) {}; \node [style=none] (9) at (2.5, 0.5) {$v_i$}; \node [style=none] (10) at (1.5, 3) {$e_i$}; \end{pgfonlayer} \begin{pgfonlayer}{edgelayer} \draw (0.center) to (1.center); \draw (1.center) to (2.center); \draw (3.center) to (4.center); \draw (4.center) to (6.center); \draw (6.center) to (5.center); \draw (5.center) to (3.center); \draw (0.center) to (2.center); \end{pgfonlayer} \end{tikzpicture}