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