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