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