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