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