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