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