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