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