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