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