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