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