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