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