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