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