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