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