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