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