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