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