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