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