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