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