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