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