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