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