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