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