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)(15,22,23,28)(16,21,18,26)(20,24,27,25)(1,2)(3,4)(6,9)(10,12)(14,19)(15,23)(21,26)(24,25) involution — undirected(2,4)(13,15,18,25,17,23,16,24)(14,20,21,22,19,27,26,28)(2,4)(13,16,17,18)(14,21,19,26)(15,24,23,25)(20,22,27,28)(5,7,8,11)(6,10,9,12)(15,23)(20,27)(22,28)(24,25)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.