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