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