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