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