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