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