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