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