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