Consider the following graph:
I can't find a planar drawing of this graph. But I want to show it formally. My approach is to use $\textbf{Kuratowski's Thoerem}$, but I can't find a Subgraph that is homeomorphic to $K_{5}$ or $K_{3,3}$. Hope somebody can help me.
$\{a,d,f\}$ and $\{b,c,e\}$ are the different sets of a $K_{3,3}$ copy. All edges are as in this bipartite graph. The whole graph is just isomorphic to it...