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