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