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