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