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