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