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