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