de Bruijn digraph

The vertices of the de Bruijn digraph $B(n,m)$ are all possible words of length $m-1$ chosen from an alphabet of size $n$.

$B(n,m)$ has $n^m$ edges consisting of each possible word of length $m$ from an alphabet of size $n$. The edge $a_1{a}_2\mathrm{\dots }{a}_n$ connects the vertex $a_1{a}_2\mathrm{\dots }{a}_{n-1}$ to the vertex $a_2{a}_3\mathrm{\dots }{a}_n$.

For example, $B(2,4)$ could be drawn as: