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