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