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