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)(16,21,26,28,25,23,24,27)(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)(16,23,26,27,25,21,24,28)(2,4)(13,16,17,26,19,25,18,24)(14,21,22,28,15,23,20,27)(16,25)(21,23)(24,26)(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.