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