One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,9)(11,12) involution — undirected(6,9)(10,12)(13,14,18,22)(15,20,24,27)(16,21,17,19)(23,28,25,26)(2,4)(14,19)(15,23)(16,17)(20,27)(21,22)(24,25) involution — undirected(5,7,8,11)(6,10,9,12)(13,15,18,24)(14,20,22,27)(16,23,17,25)(19,26,21,28)(13,16)(17,18)(19,21)(20,28)(23,25)(26,27) 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.