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