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