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)(25,26,30,35)(27,34,37,31)(28,38,36,32)(29,33,39,40)(1,3,4,7)(2,5,6,8)(9,11)(10,15)(12,19)(13,20)(14,21)(16,18)(17,22)(23,24)(25,27,30,37)(26,31,35,34)(28,29,36,39)(32,33,38,40)(1,2)(3,5)(4,6)(7,8)(9,11,14,21)(10,15,18,16)(12,19,17,22)(13,20,23,24)(25,28,30,36)(26,32,35,38)(27,29,37,39)(31,33,34,40)(9,11)(10,16)(12,22)(13,20)(14,21)(15,18)(17,19)(23,24)(25,29,30,39)(26,33,35,40)(27,36,37,28)(31,38,34,32)(1,3)(2,5)(4,7)(6,8)(9,12)(10,13)(11,19)(14,17)(15,20)(16,24)(18,23)(21,22)(25,27)(26,34)(28,29)(30,37)(31,35)(32,40)(33,38)(36,39) 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)(25,26)(27,31)(28,32)(29,33)(30,35)(34,37)(36,38)(39,40) involution — undirectedA 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.