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