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