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