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