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