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