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