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