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