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