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