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