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