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