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