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