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