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