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