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