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