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