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