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