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