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