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