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