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