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