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