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