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