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