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