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