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