Define Cayley graph as following:
G is finite group. C $\subseteq$ G such that C does not contain identity element of G and g-1 $\in$ C for all g $\in$ C. Cayley graph X(G,C) is formed with vertices V(X)=G, edges E(X)={(a,b): a,b $\in$ G, ab-1 $\in$ C}.
The k-cube is the graph with vertex set {0,1}k such that any two vertices x,y $\in$ {0,1}k are joined by an edge if and only if x and y differ in exactly one coordinate. Show that the k-cube is a Cayley graph.
Hint: Try $G=\mathbb Z_2^k$ and let $C$ be the set of $k$-tuples with $1$ in one coordinate and $0$ in every other.