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