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