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