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