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