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