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