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