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