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)(11,15)(12,20)(13,18)(14,16)(17,22)(19,24)(21,23)(25,26,30,29)(27,33,35,31)(28,36,37,32)(34,38,40,39)(1,3,5,8)(2,6,4,7)(9,11,14,13)(10,15,16,18)(12,19,22,21)(17,23,20,24)(25,27)(26,31)(28,34)(29,33)(30,35)(32,38)(36,39)(37,40)(1,2,5,4)(3,6,8,7)(10,16)(15,18)(17,20)(23,24)(25,26,30,29)(27,33,35,31)(28,32,37,36)(34,39,40,38)(1,2,5,4)(3,6,8,7)(9,10)(11,15)(12,17)(13,18)(14,16)(19,23)(20,22)(21,24)(25,28,30,37)(26,32,29,36)(27,34,35,40)(31,38,33,39)(1,4,5,2)(3,7,8,6)(9,12,14,22)(10,17,16,20)(11,19,13,21)(15,23,18,24)(25,29,30,26)(27,33,35,31)(28,36,37,32)(34,39,40,38)(9,13,14,11)(10,18,16,15)(12,21,22,19)(17,24,20,23)(25,27)(26,33)(28,34)(29,31)(30,35)(32,39)(36,38)(37,40)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.