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