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)(14,18)(15,21)(16,24)(19,23)(22,26)(27,28)(1,3,4,2)(5,7)(6,9)(8,12)(10,11)(13,14,17,18)(15,21,23,19)(16,20,24,25)(22,27,28,26)(7,12)(9,11)(13,15,18,21,17,23,14,19)(16,22,25,27,24,28,20,26)(6,10)(9,11)(13,16)(14,20)(15,22)(17,24)(18,25)(19,26)(21,27)(23,28) involution — undirected(15,23)(16,24)(19,21)(20,25) 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.