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