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