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