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