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