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