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