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