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