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