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