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