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