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)(16,24,25,19)(23,26,27,28)(2,4)(6,10)(8,11)(13,15,17,14,18,20,22,21)(16,23,26,19,25,27,28,24)(2,4)(5,6)(7,8)(9,10)(11,12)(13,16)(14,19)(15,23)(17,26)(18,25)(20,27)(21,24)(22,28) involution — undirected(5,7,9,12)(6,11,10,8)(5,8,9,11)(6,7,10,12)(16,25)(19,24)(23,27)(26,28)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.