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