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