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