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