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