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