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