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