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