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