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