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