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