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