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