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