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