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