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