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