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