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