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