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