One vertex per element, one color per generator, with an edge from x to x·s.
(3,7)(6,8)(9,10,13,12)(11,15,16,14)(17,18,20,22)(19,23,24,21)(25,26,30,31)(27,35,36,32)(28,38,39,33)(29,37,40,34)(1,2,5,4)(3,6,7,8)(9,10,13,12)(11,14,16,15)(17,18,20,22)(19,21,24,23)(26,31)(27,36)(33,38)(34,37)(9,11)(10,14)(12,15)(13,16)(17,18)(19,21)(20,22)(23,24)(25,27,30,36)(26,32,31,35)(28,37,39,34)(29,33,40,38)(1,3)(2,6)(4,8)(5,7)(9,12,13,10)(11,15,16,14)(25,28,30,39)(26,33,31,38)(27,37,36,34)(29,32,40,35)(1,4,5,2)(3,8,7,6)(9,11)(10,14)(12,15)(13,16)(17,19,20,24)(18,21,22,23)(25,29,30,40)(26,34,31,37)(27,33,36,38)(28,35,39,32)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.