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