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