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