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