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