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