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