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