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