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