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