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