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