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