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