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