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