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