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