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