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