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