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