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