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