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