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