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