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