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