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