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