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