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