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)(11,12)(13,21)(14,15)(16,19)(17,22)(18,23)(20,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,39)(36,40)(37,38)(2,6)(4,7)(10,15)(12,16)(17,21)(20,23)(25,27,30,33)(26,31,29,35)(28,34,38,36)(32,39,37,40)(1,2)(3,4)(5,6)(7,8)(10,15)(12,16)(13,22)(18,24)(26,29)(27,33)(32,37)(34,36) involution — undirected(1,3)(2,4)(5,8)(6,7)(9,11,14,19)(10,16,15,12)(13,18,22,24)(17,23,21,20)(25,28)(26,32)(27,34)(29,37)(30,38)(31,39)(33,36)(35,40)(1,4)(2,3)(5,7)(6,8)(9,12,14,16)(10,11,15,19)(13,20,22,23)(17,18,21,24)(25,27)(26,31)(28,36)(29,35)(30,33)(32,40)(34,38)(37,39)(1,3)(2,4)(5,8)(6,7)(9,13)(10,17)(11,18)(12,20)(14,22)(15,21)(16,23)(19,24)(25,29,30,26)(27,35,33,31)(28,37,38,32)(34,40,36,39)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.