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