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