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