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