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