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