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