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