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