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