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