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