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