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