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)(13,21)(14,19)(15,20)(16,18)(17,23)(22,26)(24,25) involution — undirected(4,7)(8,10)(11,13)(12,17)(14,22)(15,23)(16,24)(18,26)(19,25)(20,21) involution — undirected(3,5)(4,8)(6,9)(7,10)(12,18)(14,16)(17,25)(19,20)(21,26)(22,24) involution — undirected(5,9)(8,10)(11,14,15,16)(12,19,20,18)(13,22,23,24)(17,25,21,26)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.