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