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)(13,14,19,20,17,22,18,15)(16,24,27,21,25,23,26,28)(6,9)(10,12)(13,15,19,14,17,20,18,22)(16,23,26,21,25,24,27,28)(2,4)(5,7)(6,10)(8,11)(9,12)(14,20)(15,22)(16,25)(18,19)(21,23)(24,28) involution — undirected(7,11)(10,12)(13,16)(14,21)(15,23)(17,25)(18,27)(19,26)(20,24)(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.