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