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