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