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