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