A Cayley graph Cay(G, S) is a graph that encodes the structure of a group G
with respect to a chosen generating set S.
Vertices correspond to elements of G. Edges are drawn from
each element g to gs for every generator s ∈ S, with each generator given its own colour.
The resulting graph reveals the group's multiplication structure visually.
Key properties:
• The graph is vertex-transitive — every vertex looks the same,
reflecting the fact that group elements are all "equivalent" under right multiplication.
• The graph is connected if and only if S generates G.
• Each vertex has out-degree |S|.
• Different choices of generating set S produce different
Cayley graphs, which is why the same group can appear as several distinct polyhedra above.
Cayley graphs are a powerful bridge between algebra and geometry: the symmetries of the graph
reflect the algebraic structure of G, and geometric properties of the graph (such as diameter
or girth) carry group-theoretic meaning.