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