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