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