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