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