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