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