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