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