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