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