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