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