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