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