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