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)(13,14,17,20)(15,19,24,27)(16,21,26,23)(18,22,28,25)(1,2,4,3)(6,9)(10,12)(13,15)(14,19)(16,25)(17,24)(18,21)(20,27)(22,26)(23,28)(1,3,4,2)(5,7,8,11)(6,10,9,12)(14,20)(15,21)(16,19)(18,28)(23,24)(26,27)(13,16,17,26)(14,21,20,23)(15,22,24,25)(18,19,28,27)(15,23)(16,19)(18,28)(21,24)(22,25)(26,27) 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.