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