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