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