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