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