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