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