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