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