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