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