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