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