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