One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4,6,9,7,5,8,10)(11,12)(13,18)(14,20)(15,19)(16,21)(17,22)(23,26)(24,25)(11,13)(12,17)(14,22)(15,24)(16,23)(18,19)(20,26)(21,25) involution — undirected(3,5,6,10,7,4,8,9)(11,13)(12,18)(14,24)(15,22)(16,23)(17,19)(20,25)(21,26)(4,5)(9,10)(11,14,16,15)(12,19,21,20)(13,22,23,24)(17,18,25,26)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.