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