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