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