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