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