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