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