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