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