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