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