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