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