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