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