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