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