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