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