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