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