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