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