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