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)(13,14,17,19)(15,21,22,28)(16,24,25,20)(18,26,27,23)(6,9)(10,11)(13,15,16,23,17,22,25,26)(14,18,20,21,19,27,24,28)(6,10)(8,12)(9,11)(13,14)(15,18)(16,20)(17,19)(21,23)(22,27)(24,25)(26,28) involution — undirected(2,4)(14,19)(15,22)(20,24)(23,26) 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.