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