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