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