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