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