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