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