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