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