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