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