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