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