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