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