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