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