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