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