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