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