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