One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,9)(6,8)(7,10)(11,12)(13,18)(14,21)(15,19)(16,25)(17,20)(22,23)(24,26) involution — undirected(3,5,7,6)(4,8,10,9)(11,13)(12,18)(14,19)(15,21)(16,26)(17,22)(20,23)(24,25)(3,5,7,6)(4,9,10,8)(11,14,16,18,17,24,15,23)(12,13,19,21,20,22,25,26)(3,6,7,5)(4,9,10,8)(11,15,17,16)(12,19,20,25)(13,21,22,26)(14,23,24,18)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.