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