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