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)(25,26,32,31)(27,36,34,29)(28,33,38,37)(30,35,39,40)(2,5)(6,7)(9,11)(10,15)(12,20)(13,17)(14,21)(16,18)(19,23)(22,24)(25,27)(26,29)(28,35)(30,33)(31,36)(32,34)(37,39)(38,40) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,16)(12,23)(15,18)(19,20)(25,28,32,38)(26,33,31,37)(27,35,34,40)(29,30,36,39)(9,12)(10,17)(11,20)(13,15)(14,23)(16,22)(18,24)(19,21)(25,29,32,36)(26,34,31,27)(28,30,38,39)(33,40,37,35)(1,2)(3,7)(4,5)(6,8)(9,11)(10,18)(12,20)(13,22)(14,21)(15,16)(17,24)(19,23)(25,30)(26,35)(27,37)(28,36)(29,38)(31,40)(32,39)(33,34) 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)(25,31,32,26)(27,36,34,29)(28,37,38,33)(30,35,39,40)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.