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