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