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