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