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)(13,14,18,16)(15,22,23,28)(17,20,27,21)(19,26,25,24)(2,4)(13,15,18,23)(14,19,16,25)(17,26,27,24)(20,22,21,28)(5,7,8,11)(6,10,9,12)(13,16,18,14)(15,22,23,28)(17,21,27,20)(19,26,25,24)(14,20)(15,23)(16,21)(17,27)(19,28)(22,25) 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.