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