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