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