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