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