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