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