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