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