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