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