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