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