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