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