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