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