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