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