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