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