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