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